p16INK4a and laminin-5gamma2 chain expression during the progression of cervical neoplasia.

p16INK4a, laminin-5gamma2 chain, and PCNA were investigated to compare the expression levels in relation to histological diagnosis and time for progression. The material consisted of 37 normal cervical tissues, 35 with different grades of CIN, and 11 invasive cervical cancers. Our results showed a reduction of basement membrane staining for laminin-5gamma2 chain from 78.4% in normal squamous epithelium to 27.8% in CIN3 (p < 0.001). The intracytoplasmic staining for laminin-5gamma2 chain increases with severity of lesion. The same trend was observed with p16INK4a and PCNA expression (p < 0.001). Co-expression of p16INK4a and PCNA was seen in 85.7% of samples. Cases that were laminin-5gamma2 chain BM - /p16INK4a+/PCNA+ have the shortest interval time (average: 46.8+/-36.3 months) for progression, while cases with laminin-5gamma2 chain BM + /p16INK4a-/PCNAPCNA--have the longest time interval (average: 110.2+/-52.7 months) (p < 0.05). Thus co-expression of p16INK4a, laminin-5gamma2 chain and PCNA may be valuable for the prediction progression of cervical neoplasia.